Method and composition for removing resist, etch residue, and copper oxide from substrates having copper, metal hardmask and low-k dielectric material

ABSTRACT

A semiconductor processing composition and method for removing photoresist, polymeric materials, etching residues and copper oxide from a substrate comprising copper, low-k dielectric material and TiN, TiNxOy or W wherein the composition includes water, at least one halide anion selected from Cl −  or Br − , and, where the metal hard mask comprises only TiN or TiNxOy, optionally at least one hydroxide source.

INCORPORATION BY REFERENCE

The entirety of U.S. patent application Ser. No. 13/209,859, filed onAug. 15, 2011, is hereby expressly incorporated herein by reference.

BACKGROUND OF THE INVENTION

The presently disclosed and claimed inventive concept(s) relates tocompositions and methods for cleaning integrated circuit substrates,and, more particularly, to compositions and methods comprising a halideanion which are effective in removing photoresist, post etch residue,and/or post planarization residue from substrates comprising copper,low-k dielectric material and metal hardmask, such as TiN, TiNxOy and W.

Devices with critical dimensions on the order of 90 nanometers (nm) haveinvolved integration of copper conductors and low-k dielectrics, andthey require alternating material deposition processes and planarizationprocesses. As the technology nodes advance to 45 nm and smaller, thedecreasing size of semiconductor devices makes achieving criticalprofile control of vies and trenches more challenging. Integratedcircuit device companies are investigating the use of metal hardmasks toimprove etch selectivity to low-k materials and thereby gain betterprofile control.

In order to obtain high yield and low resistance interconnects, thepolymers on the sidewalls and the particulate/polymer residues at thevia bottoms that are generated during etching must be removed prior tothe next process step. It would be very beneficial if the cleaningsolution can also effectively etch the selected hardmask to form anintermediate morphology, e.g., a pulled-back/rounded morphology. Apulled-back/rounded morphology could prevent undercutting the hardmask,which, in turn, could enable reliable deposition of barrier metal, Cuseed layer and Cu filling. Alternatively, fully removing the metalhardmask using the same composition could offer numerous benefits todownstream process steps, particularly chemical mechanical polishing(CMP), by eliminating a need for barrier CMP.

Following almost every step in the fabrication process, e.g., aplanarization step, a trenching step, or an etching step, cleaningprocesses are required to remove residues of the plasma etch, oxidizer,abrasive, metal and/or other liquids or particles that remain and whichcan contaminate the surface of the device if not effectively removed.Fabrication of advanced generation devices that require copperconductors and low-k dielectric materials (typically carbon-silica orporous silica materials), give rise to the problem that both materialscan react with and be damaged by various classes of prior art cleaners.

Low-k dielectrics, in particular, may be damaged in the cleaning processas evidenced by etching, changes in porosity/size, and ultimatelychanges in dielectric properties. Time required to remove residuesdepends on the nature of the residue, the process (heating,crosslinking, etching, baking, and/or ashing) by which it is created,and whether batch or single wafer cleaning processes are used. Someresidues may be cleaned in a very short period of time, while someresidues require much longer cleaning processes. Compatibility with boththe low-k dielectric and with the copper conductor over the duration ofcontact with the cleaner is a desired characteristic.

When TiN, TiNxOy or W is used as an etching hard mask to gain highselectivity to low-k materials during a dry etching process inprocessing advanced copper/low-k semiconductor devices, effectivecleaning compositions that can selectively etch TiN, TiNxOy or W mustnot only be compatible with copper and the low-k materials, but mustalso be effective in simultaneously removing polymeric materials andetch residues.

With the continuing reduction in device critical dimensions andcontinuing needs for production efficiency and device performance, thereis a need for improved cleaning compositions.

SUMMARY OF THE INVENTION

The presently claimed and disclosed inventive concept(s) relate to animproved semiconductor processing composition, i.e., a wet cleaningformulation, for removing photoresist, polymeric materials, etchingresidues and copper oxide from substrates wherein the substratecomprises copper, a low-k dielectric material(s) and metal hard maskselected from TiN, TiNxOy or W. The composition comprises water, atleast one halide anion selected from Cl⁻ or Br⁻, and at least oneoxidizing agent. Although not required for carrying out the invention,at least one Cu corrosion inhibitor may also be present in thecomposition where the composition is to be deployed in semiconductorprocessing at FEOL applications and other applications where corrosionof Cu components is not a concern. In cases where the metal hard mask isTiN or TiNxOy, the composition in one embodiment will also include abase, i.e., hydroxide source, as appropriate to maintain the pH of thecomposition at a value of at least 7 or above for best results.

In some cases where the metal hard mask is TIN or TiNxOy, thecomposition in an alternate embodiment may have a pH at a value of lessthan 7, and even as low as 4.6, and achieve satisfactory results.

In cases where the metal hard mask is W, the pH working range accordingto yet another embodiment can be basic or acidic and achievesatisfactory results.

The oxidizing agent is selected from the group consisting of hydrogenperoxide, ozone, ferric chloride, permanganate, peroxoborate,perchlorate, persulfate, ammonium peroxydisulfate, per acetic acid, ureahydroperoxide, percarbonate, perborate, and mixtures thereof. Whenpresent, the Cu corrosion inhibitor is selected from the groupconsisting of a heterocyclic compound which contains a nitrogen atom inthe form of ═N— as a ring form member. The heterocyclic compound can beused singly or the Cu corrosion inhibitor can comprise a mixture of suchheterocyclic compounds. In addition, mercaptan, thiourea, aromatichydrazides, Schiff bases, indoles and derivatives thereof may alsoproduce satisfactory results in inhibiting Cu corrosion.

In another embodiment the invention comprises a method forsimultaneously removing one or more of photoresist, polymeric materials,etching residues and copper oxide from a substrate comprising copper,low-k dielectric material and TiN, TiNxOy or W. The method comprisesapplying to the substrate an aqueous composition consisting essentiallyof at least one halide anion selected from Cl⁻ or Br⁻, at least oneoxidizing agent selected from the group set forth above, and optionallyat least one Cu corrosion inhibitor selected from the group set forthabove. In cases where the metal hard mask is TiN or TiNxOy, thecomposition may also include a base, i.e., hydroxide source, asappropriate to maintain the pH of the composition at a value of at least7 or above for best results. In some cases where the metal hard mask isTiN or TiNxOy, the composition in an alternate embodiment may have a pHat a value of less than 7, and even as low as 4.6, and achievesatisfactory results. In cases where the metal hard mask is W, the pHworking range can be basic or acidic and achieve satisfactory results.The amount of undesirable residue to be removed in any given processingstep will influence the selection of operating pH value for thecomposition.

The compositions and method according to the inventive conceptsdescribed herein are uniquely capable of selectively etching TiN, TiNxOyor W, are compatible with Cu and low-k dielectric materials, and canalso simultaneously remove copper oxides, polymeric materials and etchresidues from the substrate being treated. A composition formulatedaccording to the invention and exhibiting an inherently high etch ratefor TiN, TiNxOy or W enables processing at low temperature, e.g.,temperatures less than 65° C. A relatively low temperature processexhibits a reduced oxidizer decomposition rate, which, in turn, extendsthe useful composition bath life. Additionally, compositions accordingto the invention which exhibit high TiN, TiNxOy or W etch rates aredesirable because they can reduce device processing time and therebyincrease device throughput. Typically, high TiN, TiNxOy or W etch rateshave been accomplished by increasing process temperatures. However, forsingle wafer process applications, the highest processing temperature isaround 65° C., which, in turn, can limit the upper end of TiN etchrates, and thereby limit complete removal of the TiN metal hardmask.Compositions according to the invention can effectively deliver highetch rates for TiN, TiNxOy or W with single wafer tool applications in atemperature range of from 20° C. to 60° C., and the TiN, TiNxOy or Wmetal hardmask can be fully removed with single wafer applicationprocess equipment if so desired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are cross-sectional diagrams of a semiconductor device asreceived and during and after processing according to the inventiveconcepts.

FIGS. 2 and 3 are graphs of metal hard mask etch rate vs. concentrationof halide anion at pH 8.7 and 30° C.

FIGS. 4 and 5 are graphs of metal hard mask etch rate vs. concentrationof halide anion at pH 7 and 30° C.

FIGS. 6 and 7 are graphs of metal hard mask etch rate vs. concentrationof halide anion at pH 8.7 and 20° C.

FIGS. 8 and 9 are graphs of metal hard mask etch rate vs. concentrationof halide anion at pH 8.7 and 55° C.

FIGS. 10A to 10I are SEM images of TiN metal hardmask removal using acomposition according to the invention.

FIGS. 11 to 14 are graphs of W metal hardmask etch rate at 30° C. and pHvalues of 3.4 and 8.7.

FIG. 15 is a graph of TEOS etch rate vs. NH₄Cl, NH₄Br, and NH₄F at 30°C. and pH 7.

FIG. 16 is a graph of TEOS etch rate vs. NH₄Cl, NH₄Br, and NH₄F at 50°C. and pH 7.

FIGS. 17A to 17D are SEM images of cleaning results for wafers asreceived and after processing with a composition according to theinvention.

FIG. 18 is a graph of TEOS etch rate vs. NH₄F and NH₄Br at 55° C. and pH7.

FIG. 19 is a graph of TEOS etch rate vs. NH₄F and NH₄Br at 55° C. and pH8.

FIG. 20 is a graph of TEOS etch rate vs. NH₄F and NH₄Cl at 55° C. and pH7.

FIG. 21 is a graph of TEOS etch rate vs. NH₄F and NH₄Cl at 55° C. and pH8.

FIG. 22 is a graph of TN etch rate vs. NH₄Br at 40° C. and pH 8.

FIG. 23 is a graph of TIN etch rate vs. NH₄Cl at 40° C. and pH 8.

DETAILED DESCRIPTION OF THE INVENTION

It is recognized that various components of the compositions of thisinvention may interact, and, therefore, any composition is expressed asthe amount of various components which, when added together, form thecomposition. Unless specifically stated otherwise, any composition givenin percent is percent by weight of that component that has been added tothe composition. When the composition is described as beingsubstantially free of a particular component, generally there arenumeric ranges provided to guide one of ordinary skill in the art towhat is meant by “substantially free,” but in all cases “substantiallyfree” encompasses the preferred embodiment where the composition istotally free of that particular component.

According to a first embodiment, the present invention is asemiconductor processing composition comprising water, at least onehalide anion selected from Cl⁻ or Br⁻, at least one oxidizing agent, andoptionally at least one hydroxide source depending on the desired pH forthe composition. Although not required for carrying out the invention,at least one Cu corrosion inhibitor may also be present in thecomposition where the composition is to be deployed in semiconductorprocessing at FEOL applications and other applications where corrosionof Cu components is not a concern. In one embodiment, the formulationspreferably have a pH of from 7.0 and higher for removing hardmaskscomprising TiN and TiNxOy. As pointed out above, in some applicationsthe formulations can produce satisfactory results when the pH is below7. For removing hardmask comprising W, the composition comprises water,at least one halide anion selected from Cl⁻ or Br⁻, at least oneoxidizing agent, and the pH value can range from acidic to basic. Atleast one Cu corrosion inhibitor may also be present. The compositionsof the invention are effective in simultaneously removing pholoresist,polymeric materials, etching residues and copper oxide from a substratewhich includes copper, low-k dielectric material and a metal hardmaskselected from TiN, TiNxOy or W. The cleaning composition can effectivelyetch the metal hardmask to form an intermediate morphology, e.g., apulled-back/rounded morphology, as shown diagrammatically in FIG. 1B.However, the composition is also capable of fully removing the metalhardmask as shown diagrammatically in FIG. 1C.

FIG. 1A is a cross sectional diagram of a semiconductor device whichshows copper conductor 10 in relationship to low-k dielectric material11, metal hardmask 12, and an interlayer insulating film 13. Theinterlayer insulating film will typically be p-TEOS (Tetra Ethyl OrthoSilicate) film or SiON (depending on the source). Etch residue, polymer,photoresist 14 remains after a typical processing step in devicefabrication.

The compositions and method according to the inventive conceptsdescribed herein are uniquely capable of selectively etching metal hardmask, e.g., TiN, TiNxOy and W, whereby the metal hardmask is onlypartially removed to form a pullback corner rounding scheme 15 as shownin FIG. 1B. An intermediate pullback corner rounding scheme is importantbecause it can prevent undercutting of the hardmask, thus enablingreliable deposition of barrier metal, Cu seed layer, and Cu filling.Alternatively, the metal hardmask can be completely removed as shown inFIG. 1C. Complete removal of the hardmask eliminates the need forbarrier CMP and subsequent post-CMP cleaning steps and thereby improvesdevice fabrication yields.

The compositions and method according to the inventive conceptsdescribed herein are particularly applicable for processing singlewaters in single wafer equipment wherein a higher processing temperaturein the range of 75° C. is desirable. However, higher temperatures areknown to contribute to degradation of the oxidizing agent which shortensbath life. It has been observed according to the inventive conceptsdescribed herein that satisfactory results can be achieved in processingmultiple wafers at substantially lower temperatures in the range of from20° C. to 60° C. to generate a TiN pullback scheme or to completelyremove TiN metal hardmask.

Cosolvent

In some embodiments of this invention, the composition can contain acosolvent that is miscible with water. Suitable cosolvents include, butare not limited to, sulfolane, N-methylpyrrolidone, anddimethylsulfoxide.

Oxidizing Agent

Oxidizing agents useful according to the inventive concept(s) areselected from any substance which removes metal electrons and raises theatomic valence and includes, but is notlimited to the group consistingof hydrogen peroxide (H₂O₂), ozone, ferric chloride, permanganateperoxoborate, perchlorate, persulfate, ammonium peroxydisulfate, peracetic acid, urea hydroperoxide, nitric acid (HNO₃), ammonium chlorite(NH₄ClO₂), ammonium chlorate (NH₄ClO₃), ammonium odate (NH₄IO₃),ammonium perborate (NH₄BO₃), ammonium perchlorate (NH₄ClO₄), ammoniumperiodate (NH₄IO₃), ammonium persulfate ((NH₄)₂S₂O₈),tetramethylammonium chlorite ((N(CH₃)₄)ClO₂), tetramethylammioniumchlorate ((N(CH₃)₄)ClO₃), tetramethylammonium iodate ((N(CH₃)₄)IO₃),tetramethylammonium perborate ((N(CH₃)₄)BO₃), tetramethylammoniumperchlorate ((N(CH₃)₄)ClO₄), tetramethylammonium periodate((N(CH₃)₄)IO₄), tetramethylammonium persulfate ((N(CH₃)₄)S₂O₈),((CO(NH₂)₂)H₂O₂), peracetic acid (CH₃(CO)OOH), and mixtures thereof.Among the foregoing, H₂O₂ is a most preferred oxidizing agent being freeof metals and provides ease of handling and lower relative cost.

The oxidizing agent or mixture thereof may be present in the compositionat from about 0.0001 wt % to about 95 wt %, and preferably, for bestresults, at from about 1 wt % to about 80 wt %.

Cu Corrosion Inhibitor

A Cu corrosion inhibitor is an optional component in the composition ofthis invention. A copper corrosion inhibitor will usually be present inthe inventive composition and associated process when used for BEOL(back end of line) applications, where the presence of a corrosioninhibitor is needed to protect copper surfaces from being etched orotherwise degraded. For other applications, including FEOL (Front End OfLine) applications, of the inventive composition and associated method,a corrosion inhibitor is not generally needed, i.e., slightetching/degradation of copper surfaces is not usually a concern, and acorrosion inhibitor is not present in the composition.

Cu Corrosion inhibitors are typically selected from the group consistingof a heterocyclic compound containing a nitrogen atom in the form of ═N—as a ring form member, such as pyrrole and derivatives thereof, pyrazoleand derivatives thereof, Imidazole and derivatives thereof, triazole andderivatives thereof, indazole and derivatives thereof and thiol-triazoleand derivatives thereof, benzotriazole, tolyltriazole,5-phenyl-benzotriazole, 5-nitro-benzotriazole,3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole,hydroxybenzotriazole, 2-(5-amino-pentyl)-benzotriazole,1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole,3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole,3-isopropyl-1,2,4-triazole, 5-phenylthiol-benzotriazole,halo-benzotriazoles (halo=F, Cl, Br or I), naphthotriazole,2-mercaptobenzimidazole (MBI), 2-mercaptobenzothiazole,4-methyl-2-phenylimidazole, 2-mercaptothiazoline, 5-aminotetrazole,5-aminotetrazole monohydrate, 5-amino-1,3,4-thiadiazole-2-thiol,2,4-diamino-6-methy-1,3,5-triazine, thiazole, triazine, methyltetrazole,1,3-dimethyl-2-imidazolidinone, 1,5-pentamethylenetetrazole,1-phenyl-5-mercaptotetrazole, diaminomethyltriazine, imidazoline thione,mercaptobenzimidazole, 4-methyl-4H-1,2,4-triazole-3-thiol,5-amino-1,3,4-thiadiazole-2-thiol, benzothiazole, and mixtures thereof.Among the foregoing, pyrazole is a preferred Cu corrosion inhibitor forease of handling and lower relative cost.

Other suitable Cu corrosion inhibitors include, but are not limited toindole, aromatic hydrazides and Schiff base compounds.

The Cu corrosion inhibitor or mixture thereof may be present in thecomposition at from about 0.0001 wt % to about 30 wt %, and preferably,for best results, at from about 0.01 wt % to about 10 wt %.

Halide Anion

The halide anion component may be selected from any chemical compoundswhich are capable of generating Cl⁻ and Br⁻ anions, such as NH₄Cl,NH₄Br, quatemary ammonium bromide, NR₄ ⁽⁺⁾Br⁽⁻⁾, or quaternary ammoniumchloride, NR₄ ⁽⁺⁾Cl⁽⁻⁾, R being an alkyl group or an aryl group.Preferred compounds include, but are not limited to, NH₄Cl and NH₄Br.

The halide anion may be present in the composition at concentrations offrom about 0.001 wt % to about 20 wt %. Best results have been observedwhen the halide anion is present in the composition in a range of fromabout 0.05 wt % to about 5 wt %.

Examples

Compositions according to the invention are now explained in detail byreference to the inventive concepts and comparative examples whichfollow, but the present invention is not limited by these examples.

The compositions shown in Tables 1A & 1B and in Table 6A, 6B & 6C wereprepared using water as the solvent, pyrazole as the Cu corrosioninhibitor, H₂O₂ as the oxidizing agent, and diglycolamine (DGA) as abase to adjust pH. (Water levels in the composition tables below aredesignated as “DI balance”, which means that water is present at a levelsuch that the weight percent of all components, including water, isequal to 100 weight percent.) The compositions shown in Table 5A wereprepared using water as the solvent, pyrazole as Cu corrosion inhibitor,H₂O₂ as the oxidizing agent, and glycolic acid (GA) to adjust pH.Composition pH can generally be adjusted using any suitable acid or base(i.e., proton source for acidic formulation or hydroxide source forbasic formulation) which does not adversely affect the semiconductordevice being treated, TiN and Cu etch rate evaluations were carried outfor ten minutes at 20° C., ten minutes at 30° C. and 40° C., and fiveminutes at 55° C. in the pH range from 7.0-9.0. TiN and Cu thicknesseswere measured using a Four Dimensions Four Point Probe Meter 333A,whereby the resistivity of the film was correlated to the thickness ofthe film remaining. The etch rate was calculated as the thickness change(before and after chemical treatment) divided by the chemical treatmenttime. Chemical solution pH was measured with a Beckman 260 pH/Temp/mVmeter. The H₂O₂ used in these experiments was semiconductor gradePURANAL (Aldrich 40267). Residue removal performance experiments wereconducted at 30° C. for 90 seconds, and the residue removal efficiencyand TiN pullback were evaluated from SEM results (Hitachi 5-5500). TEOSetch rate experiments were conducted at 30° C., 50′C and at 55′C for 30minutes, respectively. The TEOS thickness was measured with Horiba JoBinYvon Auto SE Spectroscopic Ellipsometer. TEOS etch rate was calculatedas the thickness change (before and after chemical treatment) divided bythe chemical treatment time.

TiN and Cu Etch Rate

The formulations shown in Table 1A & 1B were prepared and TiN and Cuetch rate evaluations were carried out as described above at atemperature of 30° C.

TABLE 1A Formulations and their pH Component Formulation NH4Br (10%)NH4Cl (10%) Pyrazole DGA (10%) DI balance H2O2 (30%) pH HCX-T002C-32- 00 0.5 0.9106 80 20 8.7 Br0-P8 HCX-T002C-32- 0.5 0 0.5 1.1345 80 20 8.7Br005-P8 HCX-T002C-32- 3 0 0.5 1.7490 80 20 8.7 Br03-P8 HCX-T002C-32- 00.5 0.5 1.0970 80 20 8.7 Cl005-P8 HCX-T002C-32- 0 3 0.5 2.2280 80 20 8.7Cl03-P8

TABLE 1B Formulations and their pH Component Formulation NH4Br (10%)NH4Cl (10%) Pyrazole DGA (10%) DI balance H2O2 (30%) pH HCX-T002C-32- 00 0.5 0.0386 80 20 7.0 Br0-P7 HCX-T002C-32- 0.5 0 0.5 0.0520 80 20 7.0Br005-P7 HCX-T002C-32- 3 0 0.5 0.0801 80 20 7.0 Br03-P7 HCX-T002C-32- 00.5 0.5 0.0383 80 20 7.1 Cl005-P7 HCX-T002C-32- 0 3 0.5 0.0440 80 20 6.9Cl03-P7

TABLE 2 TiN and Cu Etch Rate for Various Formulations at 30° C. ProcessTemp Formulation (° C.) TiN (Å/min) Cu (Å/min) HCX-T002C-32-P8 30 19.050.32 HCX-T002C-32-Br005-P8 31.39 0.61 HCX-T002C-32-Br03-P8 40.53 0.58HCX-T002C-32-Cl005-P8 34.42 0.51 HCX-T002C-32-Cl03-P8 47.03 1.05HCX-T002C-32-P7 2.74 −0.23 HCX-T002C-32-Br005-P7 6.92 0.15HCX-T002C-32-Br03-P7 11.14 −0.26 HCX-T002C-32-Cl005-P7 9.56 0.20HCX-T002C-32-Cl03-P7 12.90 0.18

The TiN etch rate results at 30° C. are shown graphically in FIGS. 2,3,4 and 5 where it can be seen that for NH₄Cl and NH₄Br the etch rate forTN metal hardmask increases as the concentration of halide anionincreases from 0 to 0.3 wt %; and low Cu etch rates in Table 2demonstrate that the chemical components of the composition arecompatible with Cu.

TiN and Cu etch rate evaluations were carried out as described above ata temperature of 20° C.

TABLE 3 TiN and Cu Etch Rate for Various Formulations at 20° C. ProcessFormulation Temp (° C.) TiN (Å/min) Cu (Å/min) HCX-T002C-32-P8 20 2.960.07 HCX-T002C-32-Br005-P8 7.57 0.01 HCX-T002C-32-Br03-P8 16.14 0.24HCX-T002C-32-Cl005-P8 9.07 0.05 HCX-T002C-32-Cl03-P8 16.06 0.37

The TiN etch rate results at 20° C. are shown graphically in FIGS. 6 and7 where it can be seen that for NH₄Cl and NH₄Br the etch rate for TiNmetal hardmask increases as the concentration of halide anion increasesfrom 0 to 0.3 wt %, and the low Cu etch rates in Table 3 show that thechemical components of the composition are compatible with Cu.

TiN and Cu etch rate evaluations were carried out as described above ata temperature of 55° C.

TABLE 4 TiN and Cu Etch Rate for Various Formulations at 55° C. ProcessFormulation Temp (° C.) TiN (Å/min) Cu (Å/min) HCX-T002C-32-P8 55 108.881.29 HCX-T002C-32-Br005-P8 120.45 0.66 HCX-T002C-32-Br03-P8 140.87 0.82HCX-T002C-32-Cl005-P8 136.47 2.40 HCX-T002C-32-Cl03-P8 145.03 5.46

The TIN etch rate at 55° C. results are shown graphically in FIGS. 8 and9 where it can be seen that for NH₄Cl and NH₄Br the etch rate for TiNmetal hardmask increases as the concentration of halide anion increasesfrom a value of 0 to 0.3 wt %, and the low Cu etch rates in Table 4indicate that the chemical components in the composition are compatiblewith Cu

SEM pictures of TiN removal are shown in FIG. 10. The TiN hardmaskpullback becomes more pronounced as the NH₄Br (or NH₄Cl) concentrationis increased from 0 to 0.05% (NH₄Br shown in FIG. 10A and FIG. 10B, andNH₄Cl shown in FIG. 10A and FIG. 10E), and TiN is completely removedwith a 0.3 wt % NH₄Br (or NH₄Cl) formulation at 40° C. (FIG. 10C andFIG. 10F). In the absence of NH₄Br (or NH₄Cl), when the processtemperature is increased from 40° C. to 50° C., the TiN pullback becomesmore significant (FIG. 10A to FIG. 10G). Complete TiN removal isachieved with a 0.3% NH₄Br (or NH₄Cl) formulation at 40° C. (FIG. 10Cand FIG. 10F), and with 0.05% NH₄Br (or NH₄Cl) at 50° C. (FIG. 10H andFIG. 10I). The results indicate that to achieve a fixed TIN etch rate(i.e., to form a specific TiN pullback morphology), a formulationcontaining NH₄Br (or NH₄Cl) requires a much lower process temperaturecompared with a formulation without NH₄Br (or NH₄Cl), and the TiN etchrate increases with increasing NH₄Br (or NH₄Cl) concentration. Theaddition of NH₄Br (or NH₄Cl) makes possible the complete removal of TINmetal hard mask with single wafer application process equipment.

W Etch Rate

The formulations shown in Table 1 and Table 5A & 5B were prepared, and Wetch rate evaluations were carried out as described above at 30° C.

TABLE 5A Formulations and W etch rate at 30° C., pH 3 W Etch RateComponent (Å/min) at Formulation Pyrazole NH4Br (10%) NH4Cl (10%) H2O2(30%) DI Balance GA (70%) 30° C. pH HCX32-0Br-p3 0.5 0 0 20 80 0.8193.67 3.4 HCX32-Br005-p3 0.5 0.5 0 20 80 0.249 25.81 3.5 HCX32-Br03-p30.5 3 0 20 80 0.238 30.22 3.4 HCX32-Cl005-p3 0.5 0 0.5 20 80 0.263 22.513.4 HCX32-Cl03-p3 0.5 0 3 20 80 0.258 31.01 3.4

TABLE 5B Formulations and W etch rate at 30° C., pH 7 and pH 8.7Formulation Process Temp (° C.) W (Å/min) HCX-T002C-32-P8 30 21.87HCX-T002C-32-Br005-P8 56.18 HCX-T002C-32-Br03-P8 97.08HCX-T002C-32-Cl005-P8 50.60 HCX-T002C-32-Cl03-P8 143.17 HCX-T002C-32-P77.11 HCX-T002C-32-Br005-P7 27.08 HCX-T002C-32-Br03-P7 31.62HCX-T002C-32-Cl005-P7 28.80 HCX-T002C-32-Cl03-P7 36.78

The results are shown graphically in FIGS. 11, 12, 13 and 14 where itcan be seen that for NH₄Cl and NH₄Br the etch rate for W metal hardmaskincreased as the concentration of halide anion increased from 0 to 0.3wt % for the pH range of from acidic to basic.

Low-K Compatibility

The compositions shown in Table 6A, 6B & 6C were prepared and TEOS etchrate evaluations were carried out as described above at temperatures of30° C. and 50° C., respectively.

TABLE 6A TEOS Etch Rate and NH₄Br Formulations at pH 7 Formulation andTEOS Etch Rate Component TEOS (30° C.) TEOS (50° C.) NH4Br H2O2 EtchRate Etch Rate Formulation (10%) BTA Pyrazole DGA (10%) DI balance (30%)(Å/min) (Å/min) pH HCX-T002C-32B-BrCl0 0 0.8 0 0.2934 80 20 −0.13 0.427.1 HCX-T002C-32B-Br03 3 0.8 0 0.3134 80 20 0.17 0.16 7.0HCX-T002C-32B-Br1 10 0.8 0 0.3288 80 20 0.22 0.36 7.0 HCX-T002C-32B-Br330 0.8 0 0.4166 80 20 0.08 0.17 7.0 HCX-T002C-32B-Br5 50 0.8 0 0.4336 8020 0.05 0.21 7.0 HCX-T002C-32-Br0 0 0 0.5 0.0386 80 20 0.01 0.17 7.0HCX-T002C-32-Br3 30 0 0.5 0.1749 80 20 0.15 0.21 7.0 HCX-T002C-32-Br5 500 0.5 0.3106 80 20 0 −0.07 7.0

TABLE 6B TEOS Etch Rate and NH₄Cl Formulations at pH 7 Formulation andTEOS Etch Rate Component TEOS (50° C.) NH4Cl H2O2 TEOS (30° C.) EtchRate Formulation (10%) BTA Pyrazole DGA (10%) DI balance (30%) Etch Rate(Å/min) (Å/min) pH HCX-T002C-32B-Cl0 0 0.8 0 0.2934 80 20 −0.13 0.42 7.1HCX-T002C-32B-Cl03 3 0.8 0 0.4396 80 20 −0.19 −0.10 7.2HCX-T002C-32B-Cl1 10 0.8 0 0.4341 80 20 0.26 0.32 7.1 HCX-T002C-32B-Cl330 0.8 0 0.5082 80 20 0.19 0.30 7.0 HCX-T002C-32B-Cl5 50 0.8 0 0.5531 8020 −0.54 0.32 7.0 HCX-T002C-32-Cl0 0 0 0.5 0.0386 80 20 0.01 0.17 7.0HCX-T002C-32-Cl3 30 0 0.5 0.2611 80 20 0.05 0.14 7.0 HCX-T002C-32-Cl5 500 0.5 0.4751 80 20 0.11 0.07 7.1

TABLE 6C TEOS Etch Rate and NH₄F Formulations at pH 7 Formulation andTEOS Etch Rate Component TEOS (30° C.) TEOS (50° C.) DI H2O2 Etch RateEtch Rate Formulation NH4F (10%) BTA Pyrazole DGA (10%) balance (30%) pH(Å/min) (Å/min) HCX-T002C-32B-F0 0 0.8 0 0.294 80 20 7 −0.13 0.42HCX-T002C-32B-F03 3 0.8 0 0.389 80 20 7 −0.07 0.28 HCX-T002C-32B-F1 100.8 0 0.387 80 20 7 0.20 0.69 HCX-T002C-32B-F3 30 0.8 0 0.343 80 20 70.44 3.59 HCX-T002C-32B-F5 50 0.8 0 0.245 80 20 7 1.78 8.88HCX-T002C-32-F0 0 0 0.5 0.031 80 20 7 0.01 0.69 HCX-T002C-32-F3 30 0 0.50.001 80 20 7 0.63 3.53 HCx-T002C-32-F5 50 0 0.5 0.000 80 20 7 1.45 8.99

TEOS etch rate results are shown graphically in FIGS. 15 and 16 where itcan be seen that with the inclusion of NH₄Cl or NH₄Br the etch rate forTEOS remains insignificant as the concentration of halide anionincreases from 0 to 5 wt %. In contrast, the TEOS etch rate increases asthe concentration of NH₄F increases from 0 to 5 wt %. The resultsindicate that compositions which contain halide anion Cl⁻ or Br⁻ do notetch TEOS. Low-k materials consist of porious TEOS, and this resultindicates that the formulations with NH₄Br (or NH₄Cl) are compatiblewith low-k materials.

Cleaning Performance

Wafers were processed as described above, and the cleaning performanceresults are shown in FIG. 17 which illustrates that etch residues aresatisfactorily removed after chemical treatments at 30° C. for 90seconds.

The compositions and method according to the inventive conceptsdescribed herein have excellent properties and are uniquely capable ofselectively etching TiN, TiNxOy or W metal hardmasks, are compatiblewith Cu and low-k dielectric materials, and can also simultaneouslyremove copper oxide, polymeric materials and etch residues from thesubstrate being treated.

Formulations and Their Performance

The formulations below are designed for all applications where corrosionof copper components during semiconductor device manufacture is not aconcern, and formulations prepared according to the inventive conceptsdescribed herein do not contain a corrosion inhibitor.

The compositions shown in Tables 7A and 7B were prepared and TEOS etchrate evaluations were carried out as described above at a temperature of55′C. Table 7A shows TEOS etch rate data measured at pH=7, while Table7B shows TEOS etch rate data measured at pH=8. The measured TEOS etchrates are summarized in Tables 7A and 7B and are shown graphically inFIGS. 18-21. It is seen from these graphs that the TEOS etch rate is notimpacted by the level of either of the ammonium bromide or ammoniumchloride level, but etch rate increases with increasing ammoniumfluoride level.

The compositions shown in Tables 7C and 7D were prepared and TIN etchrate evaluations were carried out as described above at a temperature of40′C. Table 7C shows TiN etch rate data measured at pH=7, while Table 7Dshows TiN etch rate data measured at pH=8. The measured TiN etch ratesare summarized in Tables 7C and 7D and are shown graphically in FIGS.22-23. It is seen from these graphs that the TiN etch rate increaseswith increasing levels of ammonium bromide, ammonium chloride, andammonium fluoride.

TABLE 7A TEOS Etch Rate at pH 7, 55° C. Component TEOS (55° C.) NH4BrNH4F NH4Cl DGA H2O2 Etch Rate Formulation (10%) (10%) (10%) (10%) DIbalance (30%) pH (Å/min) HCX33-F0-7 0 0 0 0.023 80 20 7 0.09 HCX33-F10-70 10 0 0.027 80 20 7 1.22 HCX33-F30-7 0 30 0 0.000 80 20 7 5.61HCX33-F50-7 0 50 0 0.000 80 20 7 12.06 HCX33-Br10-7 31.6 0 0 0.206 80 207 0.20 HCX33-Br30-7 94.7 0 0 0.532 80 20 7 0.19 HCX33-Br50-7 157.8 0 00.844 80 20 7 0.19 HCX33-Cl10-7 0 0 14.4 0.136 80 20 7 0.06 HCX33-Cl30-70 0 43.3 0.327 80 20 7 −0.01 HCX33-Cl50-7 0 0 72.2 0.461 80 20 7 0.07*Formulations with Br and Cl in the designated name contain NH₄Br andNH₄Cl, respectively.

TABLE 7B TEOS Etch Rate at pH 8, 55° C. Component TEOS (55° C.) NH4BrNH4F NH4Cl DGA H2O2 Etch Rate Formulation (10%) (10%) (10%) (10%) DIbalance (30%) pH (Å/min) HCX33-F0-8 0 0 0 0.017 80 20 8 0.13 HCX33-F10-80 10 0 0.100 80 20 8 1.17 HCX33-F30-8 0 30 0 0.204 80 20 8 2.69HCX33-F50-8 0 50 0 0.294 80 20 8 4.54 HCX33-Br10-8 31.6 0 0 0.179 80 208 0.67 HCX33-Br30-8 94.7 0 0 0.417 80 20 8 0.79 HCX33-Br50-8 157.8 0 00.672 80 20 8 0.93 HCX33-Cl10-8 0 0 14.4 0.124 80 20 8 0.33 HCX33-Cl30-80 0 43.3 0.295 80 20 8 0.25 HCX33-Cl50-8 0 0 72.2 0.431 80 20 8 0.40*Formulations with Br and Cl in the designated name contain NH₄Br andNH₄Cl, respectively.

TABLE 7C TiN Etch Rate at pH 7, 40° C. Component TiN (40° C.) NH4BrNH4Cl DI Etch Rate Formulation (10%) (10%) DGA (10%) balance H2O2 (30%)pH (Å/min) HCX33-Br0-7 0 0 0.036 80 20 7 8.59 HCX33-Br05-7 0.5 0 0.03780 20 7 15.88 HCX33-Br3-7 3 0 0.052 80 20 7 21.11 HCX33-Br5-7 5 0 0.07180 20 7 24.41 HCX33-Cl0-7 0 0 0.038 80 20 7 9.87 HCX33-Cl05-7 0 0.50.041 80 20 7 18.89 HCX33-Cl3-7 0 3 0.066 80 20 7 24.96 HCX33-Cl5-7 0 50.084 80 20 7 25.93 *Formulations with Br and Cl in the designated namecontain NH₄Br and NH₄Cl, respectively.

TABLE 7D TiN Etch Rate at pH 8, 40° C. Component TiN (40° C.) NH4BrNH4Cl DI Etch Rate Formulation (10%) (10%) DGA (10%) balance H2O2 (30%)pH (Å/min) HCX33-Br0-8 0 0 0.134 80 20 8 19.30 HCX33-Br05-8 0.5 0 0.20780 20 8 30.59 HCX33-Br3-8 3 0 0.335 80 20 8 36.28 HCX33-Br5-8 5 0 0.47080 20 8 39.52 HCX33-Cl0-8 0 0 0.116 80 20 8 17.09 HCX33-Cl05-8 0 0.50.265 80 20 8 37.24 HCX33-Cl3-8 0 3 0.593 80 20 8 43.26 HCX33-Cl5-8 0 50.742 80 20 8 48.2 *Formulations with Br and Cl in the designated namecontain NH₄Br and NH₄Cl, respectively.

1. (canceled)
 2. (canceled)
 3. (canceled)
 4. (canceled)
 5. (canceled) 6.(canceled)
 7. (canceled)
 8. A method for simultaneously removingpolymeric materials and etch residues and selectively etching TiN orTiNxOy from a semiconductor device comprising Cu, low-k dielectricmaterial and TiN or TiNxOy which comprises: contacting the semiconductordevice with an aqueous composition comprising at least one halide anionselected from Cl— or Br—, and at least one oxidizing agent in theabsence of a Cu corrosion inhibitor and wherein the composition iseffective in removing polymeric materials and etch residues andselectively etching TiN or TiNxOy from a semiconductor device comprisingCu, low-k dielectric material and TiN or TiNxOy.
 9. The method of claim8 wherein the composition includes a hydroxide source at a concentrationsufficient to adjust the pH thereof to a value of at least 7.0 orhigher.
 10. The method of claim 8 wherein the temperature is in therange of from 20° C. to about 60° C. and the oxidizing agent is selectedfrom the group consisting of hydrogen peroxide, ozone, ferric chloride,permanganate, peroxoborate, perchlorate, persulfate, ammoniumperoxydisulfate, per acetic acid, urea hydroperoxide, percarbonate,perborate, and mixtures thereof.
 11. The method of claim 8 wherein thecomposition includes a Cu corrosion inhibitor selected from the groupconsisting of heterocyclic compounds which contain a nitrogen atom inthe form of ═N— as a ring form member, and mixtures thereof.